Automatic lock for elevator doors



Oct. l1, 1932. c. E. lvl-:s

AUTOMATIC LOCK FOR ELEVATOR DOORS 2 Sheets-Sheet 1 0|:.`1l, 1932. c. E. lvEs' 1,882,621

AUTOMATIC Loox FOR ELEvAToR Dooas Filed Aug. 10'. 1927 2 Sheets-Sheet 2 :IE E -gm E (Yay/ordi? fyes.

A T TORNE 1 Patented Oct. 11, 1932 NT STATES CLIFFORD IVES, OF CHICAGO, ILLINOIS AUTOMATIC' LOCK FOR ELEVATOR DOORS Application filed August 10, 1927. Serial No. 212,002.

Myinvention relates in general to elevator locks. It relates more particularly to an automatic lock for elevator shaft doors adapted to hold the sliding shaft doors closed eX- cept when the elevator is in proper position with respect thereto and which will also prevent operation of the elevator when the doors are open.

My prior Patent No. 1,611,116, discloses an elevator lock of this general type which was a considerable improvement over the art. In these elevator locks however, the arrangement was such that the current interrupting contact points were located at the iioors; that is it was necessary to extend the wiring throughout the'full length of travel of the elevator and connect all of the current interrupting points in series.

One of the principal objects ofmy present invention is to provide a single pair of contacts for interrupting the current when the elevator shaft doors are open.

Another object is to provide an elevator lock of improved mechanicalconstruction.

Another object is to provide an elevator lock in which the mechanical and electrical elements are separated from each other.

Another Objectis to provide an improved current controlling system for an elevator adapted to cooperate with a lock of the type described.

For a complete understanding of the invention including additional objects and features thereof, reference may be had to the accompanying drawings, wherein Fig. 1 is aschematic representation of an elevator equipped with my improved device;

Fig. 2 is a fragmentary sectional view taken along the line 2-2 of Fig. 1 looking in the direction of the arrows; K

Fig. 3 is a sectional view taken along the line 3 3 of Fig. 2, showing the lock in an operative position;

Fig. t is a sectional view showing the same mechanism as Fig. 3 but with the parts in the position which they assume with the door closed but with the elevator in position to permit the opening of the door;

Fig. 5 is asimilar section showing the position which the parts assume when the door is opened;

Fig. 6 is a perspective view of a portion of the lock;

Fig. 7 is a perspective of the locking lever;

Fig. 8 is a face view of a portion of the lock applied to the elevator shaft;

Fig. 9 is a side view of the lock partially in section, showing a portion of the lock carried by the elevator, with the partsin the position in whichthe shaft door is locked; and

Fig. 10 is a similar view with the part-s in position in which the shaft `door is adapted to be opened.

The lock as shown in the drawings is applied to an elevator with a vertically sliding door such as those usually employed with freight elevators. rlhe lock is so arranged that the shaft door cannot be opened except when the elevator is even with the floor at which the door is located. This causes a partial actuation of the lock which will permit the door to be opened by hand, this door of course being provided with the usual counterbalancing weights. rll`he opening of the door further actuates the lock to operate a pair of electrical contacts carried on the elevator to prevent application of power therethrough while the door is open. The reverse action takes place when the door is closed, namely that after closing the same, the elevator can be moved, but until the elevator is moved the door can be opened at any time. p Y i Referring to Fig. 1, the usual elevator 'car 10 is suspended from cables 11 which extend over the top of an idling pulley 12 and connect with a counter weight 13, the cable being taken up on a suitable capstan (not shown) driven by suitable means as for instance an electric motor, which is controlled by a reversing controller' carried on the elevator. The elevator travels in the usual open shaft surrounded by a partition la' having at the front thereof, guideways 16 through which a door 17 is vertically reciprocable. This door is normally closed but is adapted to be opened when the lock is in proper position to permit access to the elevator for purpose of loading and `unloading the same.

,The lock comprises two maj or portions indicated by the reference characters A and E, the unit A being carried by the elevator car while the unit B is suitably secured to the partition 14 immediately adjacent a guideway 16. Unit B includes the lock proper through the instrumentality of which the door is locked, the portion A is primarily for the purpose of preventing actuation of the car while the elevator door is opened. W'hile the function of the two parts is different they are interdependent and together constitute the complete lock.

The part B carried bythe partition adj acent the elevator includes a housing 21 secured to the partition by screws or the like and having a transverse shaft 22 rotatably secured therein. @ne end of the shaft projecting beyond the wall of the housing has secured thereon an actuating arm 23 to the lower end of which is secured an actuating roller 24. Within the housing is a depending reversing lever 26 secured on the shaft by a pin 27 and having a spring 28 engaging its hub and adapted to bear against the top of the housing, the spring tending to force the depending lever and shaft in a clockwise direction. Immediately adjacent the depending lever and journaled on the shaft, is a detent 29 also provided with a spring 31 tending to force the detent in a clockwise di- Iection.` rlfhe detent is provided with a slot 32 into which a lug 33 carried by the depending reversing lever 26, ext-ends and by means of which the detent is moved.

Immediately below the shaft 22, is another Shorter transverse shaft 36 carrying a locking lever 37. The locking lever (shown in perspective in Fig. 7) has a detent engaging tip 3S and a lug 39 for engaging the depending lever 26 in a manner which will be described hereinafter. This locking lever is also provided with a shaft hole 41 in which is secured the stub shaft of a door engaging roller 42 A. spring 43 is disposed with re- Spect. tothe shaft 36 and housing, so that the locking lever will at all times be forced in a clockwise direction, or so that the door engaging roller 42 will project into the guideway 16.

Reference may now be had to unit A which comprises a housing 46 carried b the elevator car and having guideways for receiving a, pair of reciprocable shafts 4" front end of which a. lock actuating cam 48 is secured by means of screws 49 49. l#Vithin the housing and engaging the inner face of the actuating cam 48 is a compression spring 51 tending at all times to force the actuating cam toward the lock.

The switch mechanism for interrupting the electrical Acurrent is also contained in the housing 46 and includes a cross piece 52 of insulating material having secured at its opposite ends, a pair of spring contacts 53 to which are electrically connected conductors 54. At the inner end of each one of the reciprocating shafts 47 is an insulating post 56 through the lower ends of which is secured a terminal engaging bar or switch bar 57.

The switch bar is adapted normally to engage across the terminals to close the circuit but may be moved for the purpose of interrupting the same when the function of the lock demands it.

In the operation of the lock, the parts are normally in the position shown in Fig. 3. In this position it is observed that the detent 29 is in the path of the detent engaging tip 36 on the locking lever and that the door engaging roller 42 is in the guideway 16. In this position the door cannot be opened because the detent furnishes a positive stop, preventing the counter clockwise rotation of thelocking lever to remove the roller from the doors path. W'hen the car is in registration with the floor however, the parts assume the position shown in Fig. 4. As illustrated, the actua-ting cam 48 has engaged the roller 24 carried by the arm 23 and the resultant depression of this arm turns the shaft 22 slightly in a counter clockwise direction. The actuating cam has this function when the parts are in this position because the spring 51 is stronger than the springs holding the shaft 22 and naturally enough the weaker spring will give. TWith the parts in this position, the door can be opened because as the edge of the door strikes the roller 42, it will depress the locking lever since the detent is no longer in the way.

As the shaft door is opened and the locking lever depressed out of the guideway 16, the lug 39 engages the depending lever 26 and this lever being secured tothe shaft 22 will cause the shaft to rotate in a clockwise direction thus carrying the arm 28 with the roller 24 with it. The actuating roller striking the cam depresses it against the force of the spring 51 and breaks the electrical contact formed between the terminals 53 and the switch bar 57. Since the current for control'- ling the actuation ofthe elevator car must fiow through the conductors 54, it follows that the breaking of this Contact will be a positive bar to the starting of the elevator while the door is opened.

As the shaft door is closed, the parts function in av reverse direction first to make it possible to actuate the elevator until the door is closed, and lastly, stop the opening of the doors when the elevator car'has-been moved.

The advantages of the present lock are easily discernible. In the first place, the door locking mechanism is small, compactT simple and positive in its operation. The electrical part of the lock is removed a considerable distance from the mechanical portion and avoids allrpossibility of short circuiting or other forms of injury, which might result with other constructions due to the rough when the elevator is at a different fioor. This might happen if the lock was tampered with or as might possibly happen, if it should fail to function properly and permit a door to be open when the elevator is not in registration with the floor adjacent thereto. This signalling eEect would result in a positive stopping of the elevator when it reached such a floor because the actuating arm instead of being depressed by the cam would itself dey press the cam as the elevator Went by and thus positively stop the same.

For purpose by making my invention clear to those skilled in the art, I have described in detail a specific embodiment thereof. It

f is obvious however, that the invention may take different forms while still eXemplifying the same general ideas and for this reason I do not restrict myself to any particular form except in so far as defined by the appended claims.

What I claim as new and desire to secure by United States Letters Patent is:

l. In an electrically controlled elevator, a circuit interrupter carried by the elevator car, a door lock at each ioor associated with the elevator shaft doors, an actuating cam on the elevator car for releasing a lock when the elevator car is in alignment with the iioor, a spring for retaining said cam in position while the shaft door is closed, means forming a part of the lock for engaging the cam to depress the same against the action of said spring when the shaft door is opened and a connection from the cam to said interrupter for actuating the interrupter when the door is opened and preventing starting the car until the door is closed.

2. A lock for an electrically controlled elevator comprising a locking lever in the path of a sliding shaft door, a detent forming a positive stop for the locking lever, an actuating cam carried by the elevator car, means actuated by the cam for moving the detent out of the path of the locking lever so that it may be forced out of the path of the sliding door, a single current interrupter carried by the elevator car and associated with the actuating cam and means including said detent moving means for depressing said cam to actuate the interrupter and render the elevator inoperative.

3. In an electrically controlled elevator, a lock with an actuating arm projecting therefrom, a locking lever projecting into the path of an elevator shaft door, a positive detent for preventing movement of the locking lever, an actuating cam on the elevator car for engaging the `actuating arm to depress the same and release the detent so that the locking lever may be engaged by the door and forced out of the path thereof, a current interrupter vassociated with the cam and having an electrical connection to the elevator controller and means forming a part of the lock and actuated when the elevator door is opened, for

moving the actuating arm to depress the cam and affect the interrupter to render the elevator car inoperable.

4. In an electrically controlled elevator, a lock with an actuating arm projecting therefrom, a locking lever normally projecting into the path of an elevator shaft door, a detent in the path of the locking lever to prevent movement thereof, an actuating `cam on the elevator car for engaging the actuating arm to depress the same, means for transmitting the motion of the actuating arm to the detent to remove the same out of the path of the locking lever, a current interrupter associated with the cam and having an electrical connection to the elevator controller, and means responsive to movement of the locking lever for moving the actuating arm when the door is opened to force the locking lever out of the path thereof, movement of the actuating arm serving to depress the cam and affect the interrupter to render the elevator car inoperable.

5. The combination defined in claim 4 wherein the actuating arm and actuating cam are both spring pressed, the spring supporting the cam being stronger so that an initial engagement between the arm and cam serves to depress the arm while reverse movement due to the opening of the door serves to depress the cam.

6. An elevator lock including a housing, having a transverse shaft therein, an actuating arm secured on the shaft, a detent adapted to be turned with the shaft, a second transverse shaft having a locking lever with a roller normally projecting in front of an elevator shaft door to prevent opening thereof and a detent engaging portion cooperating with the detent to form a positive stop, and a cam carried by the elevator car for engaging the actuating arm to rotate the shaft and move the detent out of engagement With the locking lever so that the door may be opened.

7. An elevator lock comprising a housing positioned adjacent an elevator shaft door and having a transverse shaft journaled therein, an actuating arm secured on the shaft, a reversing lever also secured on the shaft, a detent loosely mounted on the shaft but engaged by said reversing lever to rotate therewith, a second transverse shaft, a locking lever mounted thereon and having a roller for engaging in front of an elevator door and a tip for engagement with the detent to lou lll)

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form arpositive' stop, a spring supported cam carried by the elevator car, and a current interrupter associated with said cam, said cam serving to release the detent to permit opening of the door, and such opening serving to move the locking lever against the reversed lever to rotate the shaft and depress the cam by reason of the movement of the actuating arm so that the current will be interrupted Vto render the elevator inoperable while the door is open.

8. In an electrically controlled elevator adapted to travel in a shaft equipped with shaft doors, a cam carried by the elevator car, a pair of electrical contacts carried by the car, a switch bar carried by the cam, a spring tending to maintain the bar in contact with the contacts, an elevator shaft' door lock having an arm adapted to be actuated by the' cam and mounted on a rotatable shaft,- a pivoted locking member projecting in front of the shaft door, a detent carried by the arm and normally engaging the lock-ing member, the actuation of the arm by said cam serving to rotate said detent to remove said detent to permit opening of said shaft door, and a lug carried by the locking' member and engaging said arm to depress the cam and remove said switch bar from engagement with the conf tacts, the opening of the shaft' door serving to remove the locking member.

In Witness whereof, I hereunto subscribe my name this 8th day of August, 1927.Y

` CLIFFORD E. IVES. 

